In the past LEDs were mainly used as status indicator lights in electronics, but with the vast improvements in technology—increasing the efficiency and the lifespan while reducing cost—LEDs have been put to many more uses. Multiple LEDs can easily be assembled together into an array, by soldering the LEDs together into a circuit, which can then be use to replace fluorescent lights and incandescent light bulbs, as respectively shown by U.S. Pat. No. 6,762,562 “Tubular housing with light emitting diodes” and U.S. Pat. No. 6,580,228 “Flexible substrate mounted solid-state light sources for use in line current lamp sockets”. LED arrays can be put to multitude of lighting uses given the major advantage of the long life span of LEDs and the minimal shift in color temperature thru the life of the LEDs. The LEDs currently available usually have a lifespan of 50,000 hours and some with a lifespan well over 100,000 hours.
There is little doubt that the lifespan and efficacy of LEDs will only increase as the technology improves. Unfortunately there is no guarantee that every LED is manufactured flawlessly and assembled without damage into a circuit such as the light array. LEDs may fail prematurely largely due to damage caused during the soldering process used to attach most LEDs to circuitry, because of the LED being sensitive to the heat needed to liquefy the solder. A solution to prevent the heat damage would be to use a mechanical process to attach the LEDs such as clamping the leads to the circuitry. However this clamping method of attachment will make production of these LED arrays more complex due to clamping forces required, the small size of the LEDs and tight packing of the LEDs needed to achieve a sufficient light output by the array. Some mechanical methods are taught in U.S. Pat. No. 5,404,282 “Multiple Light Emitting Diode Module” but the spacing between the adjacent LEDs is fairly large due to the clearance needed for the mechanical methods of attachment. The tight packing needed to produce a high light output will not be possible with the mechanical methods. Also the LEDs are permanently attached to its circuitry. This need for a high density of LEDs in combination with the shape of the array can even make soldering a difficult process as seen in the methods utilized in U.S. Pat. Nos. 6,762,562 and 6,580,228 Both patents teach of soldering LEDs onto a flexible flat circuit board/substrate and then bending the circuit board/substrate with the attached LEDs into its final desired shape. The need for the flexible circuit board/substrate is due to the tight spacing of the final shape, making it impossible to solder the LEDs on to a circuit already in the final shape. Unfortunately the flexible circuit board/substrate would be very fragile due to thinness of the circuit board needed to achieve the flexibility. The handling and process of bending the array into the final shape can easily break the electrical circuit, solder joins or LEDs given the thin circuit board/substrate and the heavier bulk of the attached LEDs and solder. The thinness of the electrical circuit would also have a higher resistance hence heating up and along with the heat generated by the LEDs can cause the electrical circuit attached to the bent substrate to expand at different rates, hence pulling it apart. This heating cause by the circuit and LEDs through normal usage and cooling when the array is off can greatly reduce the life of the light array, warping the shape and stressing the circuitry. The flexible circuit board/substrate may also delaminate and crack due to the characteristic differences of the materials and the constant stress caused by the bending. Also the risk of heat damage to LEDs during the soldering process is still not eliminated. U.S. Pat. No. 6,406,173 “Vehicle lamp having light-emitting elements with connecting structure” teaches of a solderless attachment method, whereby a LED with bifurcated lead terminals is used to cut into and mechanically fasten to a thin cylindrical wire. U.S. Pat. No. 6,406,173 avoids soldering, but substantially decreases electrical contact due to the fact that the bifurcated lead terminals must be relatively thin and have a sufficiently sharp edge to cut into the wire and that the contact area between the terminal and wire is limited to where the thin straight edges of lead terminal are tangent to the small diameter wire. Also the LED of U.S. Pat. No. 6,406,173 is not design to be removable. The LED assembly process currently known in the art is very limiting in what can be constructed and the arrays that can be constructed may not be very sturdy.
Yet another problem is when a single LED does fail in a light array—due to heat damage during assembly or production flaw in the LED package—there is currently no easy way to replace just that single defective LED. This usually meant putting up with having one or more blacked out spots in the light array until there are enough individual LED failures to warrant replacing the entire array. This problem with the LED array is neither pleasing to look at, nor very cost effective given the remaining unused lifespan of the still functional LEDs within the array that must be discarded if the array is to be replaced. These reasons and the difficulty of manufacturing the arrays has hampered the wide spread use of LED array based lighting by consumers. Hence a need has been recognized for a method to simplify and improve the process of attaching LEDs to circuitry and allows for easy replacement of faulty LEDs, or other small high efficiency lights, such as OLEDs, PLEDs, etc which hence fore will be referred to as a LED. One can try simply plugging the LED leads in to a breadboard type circuit but the leads need to be sufficiently long to ensure good contact for electrical and thermal conduction. Unfortunately long LED leads are easily bent and will be difficult to insert into the breadboard. The breadboard itself is also costly to manufacture due to the complex circuitry and contacts, and is of limited life as the insertion and removal can wear and loosen the contacts in the breadboard. Hence to ensure a good electrical contact and good heat dissipation the LEDs leads are currently still mostly solder or mechanically clamped permanently to its power circuitry due the small surface area of the leads and difficultly of maintaining a good contact between the lead and the circuit. Another solution currently being used is to assemble a couple of LEDs which maybe of several colors in to a single smaller module, which is then assembled into larger arrays. The modules are replaceable, but not the individual LEDs within the modules. Unfortunately these units are relatively costly to manufacture, cannot achieve the same density of LEDs as with the array of individual LEDs and are still susceptible to the damage cause during assembly of the LEDs into the module circuit. Also the discarding of perfectly functional LEDs within a flawed module when being replace is still not avoided, wasting perfectly usable LEDs. A better solution for attachment and connection of LEDs to circuits, which would enable replacement of individual broken LEDs, while minimizing cost is still needed.